Q. We often encounter flat roofs with decks over them. What roofing material makes the most sense for this?

A.Most flat roofing systems can be used under decks if the roof surface is properly protected. With built-up or single-ply systems, build the deck on sleepers, with an extra layer of roofing where the sleepers rest. The deck should be built in sections so it can be removed for cleaning, and to get to the membrane for repairs.

While I have not had personal experience with it, one new product, Duradek, is made to be used as both the deck and the roofing. It is made with a type of PVC, and is available in several colors. A brochure showing the colors and a listing of distributors is available free from Ensurco Duradek, P.O. Box F-195-37, Blaine, WA 98230; 604/591-5594.